In brake systems, it is common to use a hydraulic booster for supplying a master cylinder with an input force to effect a brake application such as disclosed in U.S. Pat. No. 5,120,115. When a traction control function is added to this type hydraulic booster in a manner as disclosed in U.S. Pat. No. 4,815,793, the total length may become an issue in a vehicle where under the hood space is limited. In order to reduce the overall length of this type hydraulic brake booster, it has been disclosed in U.S. Pat. No. 4,843,819 to use parallel boost pistons, which are connected to a master cylinder. However, when under the hood space is critical, a brake booster of the type disclosed in U.S. Pat. No. 4,514,981 has been used to control the supply of pressurized fluid to effect a brake application. These hydraulic brake boosters have satisfied many of the operational requirements of vehicle braking systems but space requirements and safety parameters continually limit the availability of current available brake boosters.